A Kurdish rebel group claims it downed a military helicopter that crashed this week in southeastern Turkey, killing all 13 personnel on board.

The Kurdistan Workers Party (PKK) said in a statement carried by the Firat news agency on June 2 that the Cougar helicopter was shot down while it was on the move in Sirnak, a province bordering Iraq and Syria.

The Turkish army had said the May 31 crash appeared to be accidental, with initial information indicating that the helicopter hit a high-voltage transmission line shortly after taking off from a base in Sirnak's Senoba region.

A major general, Aydogan Aydin, was among those killed.

The PKK has been fighting a decades-long insurgency in Turkey. Peace talks and a cease-fire between the Kurdish group and the Turkish government collapsed in 2015.